Nope, never. Had one where I rode miles up a road closed to traffic to get to where I had planned to start a ride and then realized the sidewall was giving out and had to limp back to the car (what would have been a real nice downhill, but no way I wanted to be at speed knowing the sidewall might go any second). But it held up. A lot better than walking 5 miles downhill in hte rain.

I've had spokes break in the middle of nowhere. A car stopped and helped. (actually had this one happen twice).

My very first ride on my mountian bike I got my laces caught up in the chain. Managed to backpedal and get free. Just in time to look up and see a nice fat rattlesnake crossing the road 10 feet in front of me. But I managed to pass the back end of the snake.

Then there was the time I bonled in the middle of nowhere. That would not have been that bad except it happened right where the buzzards were feasting on roadkill. Not a comfortable feeling. But they did not get the big meal, so I guess something went right.